losing oil, and it's not leaking out

[jim97gst]

I seem to be going though oil quite quickly lately, and I don't have any leaks. So the oil must be getting burned, right? So it must be either the engine or the turbo. If I do a compression test, and everything looks good, can I be pretty certain it is the turbo? I suspect the turbo. It is the stock T25 with around 70K, engine is the same. I have not babied the T25 at all. I tried checking the compressor wheel for shaft play, but I don't have a reference point. It moves a little, but I don't know what's normal. I don't notice smoke coming out of the tailpipe, but I'm not behind the car. If it is smoking, it's not enough for me to see in the rear view mirror. Even if I see the smoke though, that doesn't really help me figure out if it's the engine or the turbo anyway, right?

 

[I-luv-em-all]

if you do a compression test and get low reading then it is probably the rings. if the compression comes out good then it can either be valve seals or turbo. when you checked for shaft play did you notice any oil in the compressor, if you did its probably done for, but thats not tragic, maybe if it was an aftermarket turbo. but if it is the turbo now is a good time to upgrade.

 

[jibberishballr]

Same problem except new turbo so its not the turbo...180 compression across the board. Is it my valve seals? Any other possible problems?

Also:
No Smoke
No Leaks

 

[donmagicjuan]

While you're probably right that it's not a new turbo, I wouldn't rule it out entirely. Did you prime it before firing up the engine when you installed it?
The quickest way to identify leaky valve stem seals is with a boost leak test. "Valve seals" are the seat surfaces that seal the combustion chamber, and would give you a low compression reading when faulty.

 

[jibberishballr]

While you're probably right that it's not a new turbo, I wouldn't rule it out entirely. Did you prime it before firing up the engine when you installed it?
The quickest way to identify leaky valve stem seals is with a boost leak test. "Valve seals" are the seat surfaces that seal the combustion chamber, and would give you a low compression reading when faulty.

I did a boost leak test and the turbo was primed before starting the engine. I just found a bunch of oil underneat the valve cover next to the sparkplug wires. What does this mean?

 

[donmagicjuan]

I just found a bunch of oil underneat the valve cover next to the sparkplug wires. What does this mean?

Generally, that's a leaking oil fill cap gasket. Not sure of the P/N right now, but you could probably find a replacement cap with gasket from an auto parts store for a few bucks.

 

[jibberishballr]

Generally, that's a leaking oil fill cap gasket. Not sure of the P/N right now, but you could probably find a replacement cap with gasket from an auto parts store for a few bucks.

well would it be that much oil. I went 600 miles and was 3 quarts low. It looks like its coming from the screws that are by the wires if that helps. You think its the oil fill cap gasket? Could it lose that much oil from that?

 

[donmagicjuan]

well would it be that much oil. I went 600 miles and was 3 quarts low. It looks like its coming from the screws that are by the wires if that helps. You think its the oil fill cap gasket? Could it lose that much oil from that?

The bolts by the wires are valve cover bolts. If you're losing that much oil and it looks like it's coming from that area, it's probably the valve cover gasket or a cracked valve cover. I thought you said you had no leaks though...

 

[jibberishballr]

The bolts by the wires are valve cover bolts. If you're losing that much oil and it looks like it's coming from that area, it's probably the valve cover gasket or a cracked valve cover. I thought you said you had no leaks though...

I couldnt find any but then i opened up the valve cover and there was a lot of oil all around that area next to the wires and the bolts. Im not sure if the oils coming from those bolts but theres definitley oil in there and a lot. Ive had a cracked valve cover before and got a new one so im guessing its not that. Ill have my mechanic take a quick look and tell me what it is. How much do you think it will cost to fix this and can you recommend me any places?

Oh and when i said no leaks i guess i meant outside of engine bay...i hadnt actually spotted any in the bay until today...sorry about that

 

[jibberishballr]

anybody have any ideas?

 

[donmagicjuan]

The cost will depend on the problem. Obviously, a cracked valve cover will be much more expensive to fix than a bad gasket. If you were the one to replace the valve cover last, did you torque the bolts to spec? Overtightening those can crack a valve cover in a heartbeat. The spec is in inch-pounds (30 to be exact), meaning you can probably get there with a nutdriver.

After you nail down the problem, I would try an auto parts store for a gasket, or search online for a replacement valve cover.

Good luck, and let us know if you find it to be something else.

 

[burntheblobs]

While you're probably right that it's not a new turbo, I wouldn't rule it out entirely. Did you prime it before firing up the engine when you installed it?
The quickest way to identify leaky valve stem seals is with a boost leak test. "Valve seals" are the seat surfaces that seal the combustion chamber, and would give you a low compression reading when faulty.

Valve seals have nothing to do with compression. The valves themselves seal the combustion chamber, not the seals. The seals are there to not allow oil to leak into the combustion chamber.

 

[donmagicjuan]

Valve seals have nothing to do with compression. The valves themselves seal the combustion chamber, not the seals. The seals are there to not allow oil to leak into the combustion chamber.

Actually, if you reread my post that you quoted, you'll see that I acknowledge the valve stem seals as exactly that. I usually refer to valve seats as responsible for sealing the combustion chamber, but many people on here for whatever reason call them the valve seals. It's hardly something worth arguing over, though.

 

[jibberishballr]

Actually, if you reread my post that you quoted, you'll see that I acknowledge the valve stem seals as exactly that. I usually refer to valve seats as responsible for sealing the combustion chamber, but many people on here for whatever reason call them the valve seals. It's hardly something worth arguing over, though.

Well would this problem have any other effect on my car. I mean it fills like my turbo hits hard then starts to stop and then hits again everyonce in a while. Would this be from the oil thing? Also what should i fix first. I dont know what to to first. I guess ill just have my mechanic take a quick look. Any other help is appreciated.

Thanks

 

[jbouvier]

I'm having a similar problem. There are no leaks other than what looked to be from my oil cap which i replaced but im still losing oil somewhere about 1qt every thousand miles. There is some smoke under boost from the tailpipe, and there is like an oily feel to the inside of the tip giving me the impression its burning it. I did a boost leak test and compression test; compression was about 133 across all cylinders, noticed white along the spark plugs, running lean i assume so i turned the boost down. Someone asked me if i did the test wet or dry. I don't know what this means or if it would entail different results. I've heard rings but i don't know how to be sure. Any ideas.